[杂项项目]纯C语言实现随机生成数独九宫格

一年前的程序，可以生成一个数独的九宫格。当时想这种方法想了3天，终于实现了。由于当时刚熟悉指针，因此指针用的比较多。本人比较懒，先把代码贴出来，后序补充具体实现方法。

#include <stdio.h>  
#include <stdlib.h>  
#include <time.h>  
  
void main()  
{  
    int a[9][9] = { 0 };  
    int *p[3][3], *m[3][6], *n[3][6], *r[9][4], *aa[9][9];  
    int **q[9];  
    int i, j, k, l, h, t, s = 0;  
    void rank(int *x, int *y);  
    bool check(int a[9][9], int n);  
    srand((int)time(0));  
  
    for (i = 0; i < 3; i++)  
        for (j = 0; j < 3; j++)  
            p[i][j] = &a[i * 3 + 1][j * 3 + 1];  
    for (k = 0; k < 9; k++)  
        q[k] = &p[k / 3][k % 3];  
    for (i = 0; i < 3; i++)  
        for (j = 0; j < 6; j++)  
        {  
            m[i][j] = &a[i * 3 + 1][2 * j - j / 2];  
            n[i][j] = &a[2 * j - j / 2][i * 3 + 1];  
        }  
    for (k = 0; k < 9; k++)  
        for (l = 0; l < 4; l++)  
            r[k][l] = &a[(k / 3) * 3 + (l / 2) * 2][(k % 3) * 3 + (l % 2) * 2];  
    for (i = 0; i < 9; i++)  
        for (j = 0; j < 9; j++)  
            aa[i][j] = &a[i][j];  
step1:  
    for (i = 0; i < 9; i++)  
    {  
    next1:  
        **q[i] = rand() % 10;  
        if (**q[i] == 0)  
            goto next1;  
        for (j = 0; j < i; j++)  
            if (**q[j] == **q[i])  
                goto next1;  
    }  
step2:  
    for (i = 0; i < 3; i++)  
        for (j = 0; j < 6; j++)  
        {  
        next2:  
            *m[i][j] = rand() % 10;  
            if (*m[i][j] == 0)  
                goto next2;  
            for (k = 0; k < 3; k++)  
                if (*m[i][j] == *p[i][k])  
                    goto next2;  
            for (k = 0; k < j; k++)  
                if (*m[i][j] == *m[i][k])  
                    goto next2;  
            for (k = 0; k < i; k++)  
                if (*m[i][j] == *m[k][j])  
                    goto step2;  
        }  
step3:  
    for (i = 0; i < 3; i++)  
    {  
    next4:  
        for (j = 0; j < 6; j++)  
        {  
        next3:  
            *n[i][j] = rand() % 10;  
            if (*n[i][j] == 0)  
                goto next3;  
            for (k = 0; k < 3; k++)  
                if (*n[i][j] == *p[k][i])  
                    goto next3;  
            for (k = 0; k < j; k++)  
                if (*n[i][j] == *n[i][k])  
                    goto next3;  
            for (l = 0; l < 2; l++)  
            {  
                if (*n[i][j] == *m[j / 2][i * 2 + l])  
                    goto next4;  
            }  
            for (k = 0; k < i; k++)  
                if (*n[i][j] == *n[k][j])  
                    goto step3;  
        }  
    }  
step4:  
    for (i = 0; i < 3; i++)  
    {  
        for (h = 0; h < 2; h++)  
        {  
        next6:  
            for (l = 0; l < 3; l++)  
                for (j = 0; j < 2; j++)  
                {  
                next5:  
                    *r[i * 3 + l][h * 2 + j] = rand() % 10;  
                    if (*r[i * 3 + l][h * 2 + j] == 0)  
                        goto next5;  
                    if (*r[i * 3 + l][h * 2 + j] == **q[i * 3 + l])  
                        goto next5;  
                    for (k = 0; k < h * 2 + j; k++)  
                        if (*r[i * 3 + l][h * 2 + j] == *r[i * 3 + l][k])  
                            goto next5;  
                    for (k = 0; k < 2; k++)  
                    {  
                        if (*r[i * 3 + l][h * 2 + j] == *m[i][l * 2 + k])  
                            goto next5;  
                        if (*r[i * 3 + l][h * 2 + j] == *n[l][i * 2 + k])  
                            goto next5;  
                    }  
                    for (k = 0; k <= l * 3 + j * 2; k++)  
                        for (t = 0; t < k; t++)  
                            if (a[i * 3 + h * 2][k] == a[i * 3 + h * 2][t])  
                                goto next6;  
                }  
        }  
    }  
step5:  
    for (i = 0; i < 3; i++)  
    {  
        if (check(a, i) == false)  
        {  
            for (j = 0; j < 9; j++)  
            {  
                rank(aa[j][i * 3], aa[j][i * 3 + 2]);  
                if (check(a, i) == false)  
                    rank(aa[j][i * 3], aa[j][i * 3 + 2]);  
                else if (check(a, i) == true)  
                    break;  
            }  
        }  
        if (check(a, i) == false)  
        {  
            for (j = 0; j < 9; j++)  
            {  
                for (k = 8; k > j; k--)  
                {  
                    rank(aa[j][i * 3], aa[j][i * 3 + 2]);  
                    rank(aa[k][i * 3], aa[k][i * 3 + 2]);  
                    if (check(a, i) == false)  
                    {  
                        rank(aa[j][i * 3], aa[j][i * 3 + 2]);  
                        rank(aa[k][i * 3], aa[k][i * 3 + 2]);  
                    }  
                    else if (check(a, i) == true)  
                        break;  
                }  
                if (check(a, i) == true)  
                    break;  
            }  
        }  
        if (check(a, i) == false)  
        {  
            for (l = 0; l < 9; l++)  
            {  
                for (j = l + 1; j < 9; j++)  
                {  
                    for (k = 8; k > j; k--)  
                    {  
                        rank(aa[l][i * 3], aa[l][i * 3 + 2]);  
                        rank(aa[j][i * 3], aa[j][i * 3 + 2]);  
                        rank(aa[k][i * 3], aa[k][i * 3 + 2]);  
                        if (check(a, i) == false)  
                        {  
                            rank(aa[l][i * 3], aa[l][i * 3 + 2]);  
                            rank(aa[j][i * 3], aa[j][i * 3 + 2]);  
                            rank(aa[k][i * 3], aa[k][i * 3 + 2]);  
                        }  
                        else if (check(a, i) == true)  
                            break;  
                    }  
                    if (check(a, i) == true)  
                        break;  
                }  
                if (check(a, i) == true)  
                    break;  
            }  
        }  
        if (check(a, i) == false)  
        {  
            for (l = 0; l < 6; l++)  
            {  
                for (h = l + 1; h < 7; h++)  
                {  
                    for (j = h + 1; j < 8; j++)  
                    {  
                        for (k = 8; k > j; k--)  
                        {  
                            rank(aa[l][i * 3], aa[l][i * 3 + 2]);  
                            rank(aa[h][i * 3], aa[h][i * 3 + 2]);  
                            rank(aa[j][i * 3], aa[j][i * 3 + 2]);  
                            rank(aa[k][i * 3], aa[k][i * 3 + 2]);  
                            if (check(a, i) == false)  
                            {  
                                rank(aa[l][i * 3], aa[l][i * 3 + 2]);  
                                rank(aa[h][i * 3], aa[h][i * 3 + 2]);  
                                rank(aa[j][i * 3], aa[j][i * 3 + 2]);  
                                rank(aa[k][i * 3], aa[k][i * 3 + 2]);  
                            }  
                            else if (check(a, i) == true)  
                                break;  
                        }  
                        if (check(a, i) == true)  
                            break;  
                    }  
                    if (check(a, i) == true)  
                        break;  
                }  
                if (check(a, i) == true)  
                    break;  
            }  
        }  
        if (check(a, i) == false)  
            goto step4;  
    }  
  
    printf("+---------------+---------------+---------------+\n");  
    printf("|               |               |               |\n");  
    for (i = 0; i < 9; i++)  
    {  
        printf("|   ");  
        for (j = 0; j < 9; j++)  
        {  
            printf("%-4d", a[i][j]);  
            if ((j + 1) % 3 == 0)  
                printf("|   ");  
        }  
        printf("\n");  
        printf("|               |               |               |\n");  
        if ((i + 1) % 3 == 0)  
        {  
            printf("+---------------+---------------+---------------+\n");  
            if (i < 8)  
                printf("|               |               |               |\n");  
        }  
    }  
  
    system("pause");  
}  
  
void rank(int *x, int *y)  
{  
    int t;  
    t = *x;  
    *x = *y;  
    *y = t;  
}  
  
bool check(int a[9][9], int n)  
{  
    int i, j;  
    for (i = 0; i < 9; i++)  
        for (j = 0; j < i; j++)  
            if (a[i][n * 3] == a[j][n * 3])  
                return false;  
    return true;  
}